Resin composition for plating substrate and resin molding using the same, and metal plated parts

ABSTRACT

The resin composition for a platable substrate of the present invention comprises 100 parts by weight of a resin composition (C) comprising 10 to 60% by weight of a graft copolymer (A) prepared by graft polymerization of a rubbery polymer (A1) and a monomer component (A2) containing an aromatic alkenyl compound monomer unit (a) and a vinyl cyanide compound monomer unit (b) and 40 to 90% by weight of the other polymer (B) (provided that the total amount of the components (A) and (B) is 100% by weight), and 5 to 40 parts by weight of a phosphate ester flame retardant (D) having a molecular weight of more than 326 or 2 to 40 parts by weight of a red phosphorus flame retardant (D′). The resin composition for a platable substrate of the present invention is excellent in production stability such as moldability, dimensional stability, mechanical strength and plating properties, and is also environmentally friendly. Excellent plated parts having good thermal conductivity can be provided by forming a metal plating layer on a resin molded article obtained by molding the resin composition for a platable substrate using a plating treatment. The resulting plated parts are suitable for use as housings for laptop PC and portable devices.

TECHNICAL FIELD

[0001] The present invention relates to a flame retardant resincomposition for a platable substrate, a resin molded article formedthereof, and plated parts.

BACKGROUND ART

[0002] As materials for housings for laptop PCs and portable devices,unreinforced or fiber-reinforced flame retardant ABS and flame retardantPC-ABS have been exclusively used heretofore.

[0003] Recently, weight reduction and thickness reduction of deviceshave been strongly demanded and it has also been required for it toendure impacts and loads when carried in a bag. Therefore, it has becomenecessary to reduce the thickness and weight of the housing and toimpart high impact resistance thereto. Thus, high rigidity and impactproperties are required from a resin used as the material of thehousing.

[0004] Also, the housing for these devices require electromagnetic waveshielding properties (hereinafter referred to as EMI shieldability). Themethod of imparting EMI shieldability includes, for example, a method ofusing a resin containing about 30% by weight or more of carbon fibers, amethod of inserting a metal foil or a metal plate upon in-molding orassembly of a product, and a method of subjecting to electroless platingor conductive coating.

[0005] Among conventionally used materials, unreinforced flame retardantABS and flame retardant PC-ABS cannot cope with recent thicknessreduction because of poor rigidity. A glass fiber-reinforced material isinsufficient in balance between rigidity and weight. In a carbonfiber-reinforced material, when using a resin containing about 30% byweight or more of carbon fibers, EMI shieldability can be obtained.However, there arises a problem in that carbon fibers are expensive andthe material containing carbon fibers in an amount of less than 30% byweight must be subjected to another treatment so as to impart sufficientEMI shieldability. Large content of carbon fibers causes a problem inthat the appearance of a resin molded article made of the materialbecomes poor.

[0006] Although laptop PCs and portable devices contain sources of heat,such as CPUs, a calorific value tends to increase because of the highdensity thereof. Also, because of thickness reduction of the housing,heat removal is considered to be an important problem.

[0007] A material having high thermal conductivity is preferably used.as the material of the housing to remove heat. Since a resin materialgenerally has low thermal conductivity, other measures must be adoptedto remove heat in order to use a housing made of the resin.

[0008] From an environmental point of view, it has been recentlyrequired to use a flame retardant material free from halogens such aschlorine or bromine, which copes with the trend toward German andSwedish Ecolabeling.

[0009] Under these circumstances, housings for laptop PC and portabledevices are required to be light weight, have thin walls, high rigidity,high impact resistance, high thermal conductivity, EMI shieldability,and be mass productible, and also require the use of an environmentallyfriendly material.

[0010] As a method of obtaining a device housing which is light weight,and has high rigidity, good thermal conductivity, and low cost, JapaneseUnexamined Patent Application, First Publication No. 2000-349486proposes a housing wherein the surface of a resin molded articleobtained by molding of a thermoplastic resin is subjected to metalplating.

[0011] However, the technique disclosed in Japanese Patent Application,First Publication No. 2000-349486 is considered to be insufficient fromthe following point of view with respect to the production of a housingwhich meets all performance requirements described above.

[0012] For example, in Example 5 of the publication, a halogen-freephosphate ester flame retardant is used as a flame retardant, but it haslow molecular weight. Therefore, the flame retardant has a low meltingpoint and is liable to vaporize (gasify) at high temperatures, and thuslarge amounts of gas are evolved during molding. Consequently, therearise problems in that evolved gas contaminates the mold surface and isdeposited on the mold parting plane (mold deposit), resulting in poorproductivity, and problems such as poor formation of a plating layer ofplated parts, and poor appearance.

DISCLOSURE OF THE INVENTION

[0013] An object of the present invention is to provide a flameretardant resin composition for a platable substrate, which is excellentin production stability such as moldability, dimensional stability,mechanical strength, and platable properties, and is alsoenvironmentally friendly and is suited for use in the production ofplated parts. Excellent platable properties as used herein means that aplated layer is free from plating blistering and has high platingadhesive strength, and also these performances are maintained even ifthe environmental temperature varies.

[0014] The present inventors have found that a composition prepared bymixing a specific resin composition with a phosphate ester flameretardant or red phosphorus flame retardant having a molecular weight of326 or more is excellent in production stability such as moldability,dimensional stability, mechanical strength and platable properties, andis also capable of excellent production of plated parts which have nothitherto been obtained, and thus the present invention has beencompleted.

[0015] The resin composition for a platable substrate of the presentinvention comprises 100 parts by weight of a resin composition (C)comprising 10 to 60% by weight of a graft copolymer (A) prepared bygraft polymerization of a rubbery polymer (A1) and a monomer component(A2) containing an aromatic alkenyl compound monomer unit (a) and avinyl cyanide compound monomer unit (b) and 40 to 90% by weight of theother polymer (B) (provided that the total amount of the components (A)and (B) is 100% by weight), and 5 to 40 parts by weight of a phosphateester flame retardant (D) having a molecular weight of more than 326 or2 to 40 parts by weight of a red phosphorus flame retardant (D′).

BEST MODE FOR CARRYING OUT THE INVENTION

[0016] The present invention will now be described in detail.

[0017] The resin composition (C) used as the resin composition for aplatable substrate of the present invention is composed of 10 to 60% byweight of a graft copolymer (A) prepared by graft polymerization of arubbery polymer (A1) and a monomer component (A2) and 40 to 90% byweight of the other polymer (B).

[0018] Examples of the rubbery polymer (A1) include butadiene rubber,styrene-butadiene rubber, acrylonitrile-butadiene rubber, isoprenerubber, chloroprene rubber, butyl rubber, ethylene-propylene rubber,ethylene-propylene-non-conjugated diene rubber, acrylic rubber,epichlorohyrin rubber, diene-acrylic composite rubber andsilicone-acrylic composite rubber. Among these polymers, butadienerubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber,acrylic rubber, diene-acrylic composite rubber and silicone-acryliccomposite rubber are preferable because a molded article of theresulting composition is excellent in plating properties.

[0019] The diene component of the diene-acrylic composite rubbercontains 50% by weight or more of butadiene. Specific examples thereofinclude butadiene rubber, styrene-butadiene rubber andacrylonitrile-butadiene rubber. The acrylic rubber component is an alkyl(meth)acrylate rubber. Examples of the composite structure of thediene-acrylic composite rubber include core shell form wherein a corelayer made of a diene rubber is coated with an alkyl (meth)acrylaterubber, core shell form wherein a core layer made of an alkyl(meth)acrylate rubber is coated with a diene rubber, form wherein adiene rubber and an alkyl (meth)acrylate rubber are mutually entangled,and a copolymer form wherein a diene monomer unit and an alkyl(meth)acrylate monomer unit are arranged at random.

[0020] The silicone component of the silicone-acrylic composite rubbercontains polyorganosiloxane as a main component and is preferablypolyorganosiloxane having a vinyl polymerizable functional group. Theacrylic rubber component is an alkyl (meth)acrylate rubber. Examples ofthe composite structure of the silicone-acrylic composite rubber includecore shell form wherein a core layer is made of a polyorganosiloxanerubber and is coated with an alkyl (meth)acrylate rubber, core shellform wherein a core layer is made of an alkyl (meth)acrylate rubber andis coated with a polyorganosiloxane rubber, form wherein apolyorganosiloxane rubber and an alkyl (meth)acrylate rubber aremutually entangled, and form wherein a segment of polyorganosiloxane anda segment of polyalkyl (meth)acrylate are linearly and sterically bondedto form a network.

[0021] The acrylic rubber component in the diene-acrylic compositerubber and the silicone-acrylic composite rubber is composed of an alkyl(meth)acrylate (g) and a polyfunctional monomer (h).

[0022] Examples of the alkyl (meth)acrylate (g) include alkyl acrylatessuch as methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butylacrylate, and 2-ethylhexyl acrylate; and alkyl methacrylates such ashexyl methacrylate, 2-ethylhexyl methacrylate, and n-laurylmethacrylate. These compounds can be used alone, or two or more kindsthereof can be used in combination. Since the finally obtained resincomposition for plating substrate is excellent in impact resistance andgloss, n-butyl acrylate is used particularly preferably.

[0023] Examples of the polyfunctional monomer (h) include allylmethacrylate, ethylene glycol dimethacrylate, propylene glycoldimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycoldimethacrylate, triallyl cyanurate, and triallyl isocyanurate. Thesemonomers can be used alone, or two or more kinds thereof can be used incombination.

[0024] Although the method of preparing the rubbery polymer (A1) used inthe present invention is not specifically limited, the polymer isusually prepared by the emulsion polymerization using a radicalpolymerization initiator because the particle diameter of the rubberypolymer (A1) is easily controlled. An average particle diameter of therubbery polymer (A1) is not specifically limited, but is preferably from0.1 to 0.6 μm so as to obtain a resin composition for a platablesubstrate which is excellent in plating properties and impactresistance. When the average particle diameter is less than 0.1 μm,impact resistance of the resin composition for a platable substratedeteriorates and plating blistering is likely to occur. On the otherhand, when the average particle diameter exceeds 0.6 μm, platingadhesive strength decreases.

[0025] The content of the rubbery polymer (A1) is preferably from 5 to25% by weight based on the resin composition (C). When the content iswithin the above range, the resin molded article made of the resincomposition for plating substrate is excellent in impact resistance andplating adhesive strength.

[0026] The monomer component (A2) used in the graft polymerization withthe rubbery polymer (A1) contains an aromatic alkenyl compound monomerunit (a) and a vinyl cyanide compound monomer unit (b) and, ifnecessary, a monomer unit (c) copolymerizable with these units. Althougha composition ratio thereof is not specifically limited, the amount ofthe aromatic alkenyl compound monomer unit (a) is preferably from 50 to90% by weight, the amount of the vinyl cyanide compound monomer unit (b)is preferably from 10 to 50% by weight, and the amount of the monomerunit (c) is preferably from 0 to 40% by weight (provided that the totalamount of the components (a), (b) and (c) is 100% by weight). When theratio is not within the above range, the resin composition for platingsubstrate is inferior in at least one of moldability and platingproperties.

[0027] The aromatic alkenyl compound monomer unit (a) includes styrene,α-methylstyrene, and vinyltoluene, and is preferably styrene. The vinylcyanide compound monomer unit (b) includes acrylonitrile andmethacrylonitrile, and is preferably acrylonitrile.

[0028] Examples of the monomer unit (c) copolymerizable with theminclude methacrylate esters such as methyl methacrylate, ethylmethacrylate, and 2-ethylhexyl methacrylate; acrylate esters such asmethyl acrylate, ethyl acrylate, and butyl acrylate; and maleimidecompounds such as N-phenylmaleimide.

[0029] The graft copolymer (A) can be obtained by the graftpolymerization of the rubbery polymer (A1) with the monomer component(A2) which serves as a graft component. A known method can be applied tothe graft polymerization and the method is not specifically limited.Upon the graft polymerization, various chain transfer agents can be usedto adjust the molecular weight and graft ratio of the graft polymer.

[0030] The graft copolymer (A) preferably contains 70 to 99% by weightof an insoluble matter in an acetone solvent and a reduced viscosity of0.30 to 0.70 dl/g as measured at 25° C. in a solution of the acetonesoluble matter (0.2 g/dl) in N,N-dimethylformamide.

[0031] As used herein, the soluble matter in the acetone solvent is anon-grafted polymer composed only of the monomer component (A2), whichis often produced upon graft copolymerization of the rubbery polymer(A1) and the monomer component (A2) which serves as a graft component.Therefore, when using the graft copolymer (A) containing 70% by weightof the insoluble matter in the acetone solvent, 30% by weight of theresidual non-grafted polymer is counted as the other copolymer (B).

[0032] The amount of the graft copolymer (A) in the resin composition(C) is from 10 to 60% by weight (based on 100% by weight of the totalamount of the components (A) and (B)). When the amount is less than 10%by weight, the impact resistance and plating adhesive strength of theresin composition for plating substrate are lowered. On the other hand,when the amount exceeds 60% by weight, flame retardancy of the resincomposition for a platable substrate deteriorates. More preferably, theamount is 25% by weight or less. When the amount of the graft copolymer(A) is less than 10% by weight or exceeds 60% by weight, thermal cycleproperties of plated parts deteriorate. As used herein, thermal cycleproperties are properties wherein blistering of the plating layer doesnot occur even if plated parts are used in an environment withalternating low and high temperature.

[0033] The other polymer (B) used in the present invention is notspecifically limited, but is preferably selected from the groupconsisting of copolymer (B-1) composed of an aromatic alkenyl compoundmonomer unit (a), a vinyl cyanide compound monomer unit (b) and, ifnecessary, a vinyl monomer unit (c) copolymerizable therewith,polycarbonate resin (B-2), polyamide resin (B-3) and polyester resin(B-4) because the resin composition for a platable substrate isexcellent in moldability and mechanical strength. These polymers can beused alone, or two or more kinds thereof can be used in combination.

[0034] Specific examples of the copolymer (B-1) includestyrene-acrylonitrile copolymer (SAN resin),α-methylstyrene-acrylonitrile copolymer,styrene-α-methylstyrene-acrylonitrile copolymer,styrene-acrylonitrile-methyl methacrylate copolymer,styrene-acrylonitrile-N-phenylmaleimide copolymer, andstyrene-acrylonitrile-maleic anhydride copolymer.

[0035] The content of the aromatic alkenyl compound monomer unit (a) inthe copolymer (B-1) is preferably within a range from 50 to 90% byweight, and more preferably from 60 to 80% by weight. The content of thevinyl cyanide compound monomer unit (b) in the copolymer (B-1) ispreferably within a range from 10 to 50% by weight, and more preferablyfrom 20 to 40% by weight. When each content of these units is within theabove range, the resulting resin composition for a platable substrate isexcellent in moldability and plating properties.

[0036] When using the vinyl compound monomer unit (c), the content ispreferably 40% by weight or less. When the content exceeds 40% byweight, the resin composition for plating substrate is sometimesinsufficient in moldability and plating properties.

[0037] The molecular weight of the copolymer (B-1) is not specificallylimited, but a reduced viscosity as measured at 25° C. in aN,N-dimethylformamide (0.2 g/dl) solution is preferably from 0.4 to 1.4dl/g.

[0038] The polycarbonate resin (B-2) is obtained fromdihydroxydiarylalkane and may be optionally branched. The polycarbonateresin (B-2) is prepared by a known method and is generally prepared byreacting a dihydroxy or polyhydroxy compound with a phosgene or adiester of carbonic acid.

[0039] Preferable dihydroxydiarylalkane has an alkyl group at theortho-position with regard to a hydroxy group. Specific examples thereofinclude 4,4-dihydroxy-2,2-diphenylpropane (=bisphenol A), tetramethylbisphenol A, and bis-(4-hydroxyphenyl)-p-diisopropylbenzene.

[0040] The branched polycarbonate can be prepared by substituting aportion, for example, 0.2 to 2% by mole of a dihydroxy compound withpolyhydroxy. Specific examples of the polyhydroxy compound includefluoroglycinol, 4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptene,4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptane, and1,3,5-tri-(4-hydroxyphenyl)-benzene.

[0041] The molecular weight of the polycarbonate resin (B-2) is notspecifically limited, but is preferably from 15000 to 35000 in terms ofa viscosity average molecular weight (Mv).

[0042] As the polyamide resin (B-3), a 3- or polymembered lactam,polymerizable ω-amino acid, or polyamide obtained by polycondensation ofdibasic acid and diamine can be used.

[0043] Examples thereof include polymers such as ε-caprolactam,aminocaproic acid, enantholactam, 7-aminoheptanoic acid,11-aminoundecanoic acid, and 9-aminonanoic acid; polymers obtained bypolycondensation of diamines such as hexamethylenediamine,nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine andmetaxylenediamine, and dicarboxylic acids such as terephthalic acid,isophthalic acid, adipic acid, sebacic acid, dodecane dibasic acid andglutaric acid; and copolymers thereof. Specific examples thereof includenylon 6, nylon 11, nylon 12, nylon 4,6, nylon 6,6, nylon 6,10, and nylon6,12.

[0044] The polyester resin (B-4) contains 50% by weight of a componentcomposed mainly of an aromatic dicarboxylic acid having 8 to 22 carbonatoms and an alkylene glycol or cycloalkylene glycol having 2 to 22carbon atoms and optionally contains a small amount of an aliphaticdicarboxylic acid such as adipic acid or sebacic acid as a constituentunit. Also, it may contain a polyalkylene glycol such as polyethyleneglycol or polytetramethylene glycol as a constituent unit. Examples ofparticularly preferable polyester resin include polyethyleneterephthalate, polybutylene terephthalate, polytetramethyleneterephthalate, and polybutylene naphthalate. These polyester resins areused alone, or two or more kinds thereof are used in combination.

[0045] As the other polymer (B), the above-described copolymer (B-1),polycarbonate resin (B-2), polyamide resin (B-3) and polyester resin(B-4) may be used alone, or two or more kinds thereof may be used incombination. Examples thereof include combinations of two kinds ofpolymers, for example, styrene-acrylonitrile copolymer (SAN resin, B-1)and polycarbonate resin (B-2), SAN resin (B-1) and polyamide resin(B-3), SAN resin (B-1) and polyester resin (B-4), and polycarbonateresin (B-2) and polyester resin (B-4); and combinations of three kindsof polymers, for example, SAN resin (B-1), polycarbonate resin (B-2) andpolyester resin (B-4). Among these combinations, combination of SANresin (B-1) and polycarbonate resin (B-2) and combination of SAN resin(B-1), polycarbonate resin (B-2) and polyester resin (B-4) arepreferable and the resulting resin composition for plating substrate isexcellent in balance between moldability and mechanical strength.

[0046] The content of the other polymer (B) in the resin composition (C)is from 40 to 90% by weight, and preferably from 50 to 80% by weight(based on 100% by weight of the total amount of the components (A) and(B)).

[0047] When two or more kinds of polymers are used in combination as theother polymer (B), the other polymer (B) preferably contains thecopolymer (B-1), polycarbonate resin (B-2), polyamide resin (B-3) andpolyester resin (B-4) in the following composition ratio.

[0048] When the styrene-acrylonitrile copolymer (SAN resin, B-1) and thepolycarbonate resin (B-2) are used in combination as the other polymer(B), the other polymer (B) preferably contains 1 to 65% by weight of thecopolymer (B-1) and 35 to 99% by weight of the polycarbonate resin (B-2)(provided that the total amount of the components (B-1) and (B-2) is100% by weight.

[0049] When the SAN resin (B-1) and the polyamide resin (B-3) are usedin combination as the other polymer (B), the other polymer (B)preferably contains 10 to 50% by weight of the copolymer (B-1) and 50 to90% by weight of the polyamide resin (B-3) (provided that the totalamount of the components (B-1) and (B-3) is 100% by weight).

[0050] When the SAN resin (B-1) and the polyester resin (B-4) are usedin combination as the other polymer (B), the other polymer (B)preferably contains 15 to 55% by weight of the copolymer (B-1) and 45 to85% by weight of the polyester resin (B-4) (provided that the totalamount of the components (B-1) and (B-4) is 100% by weight).

[0051] When the polycarbonate resin (B-2) and the polyester resin (B-4)are used in combination as the polymer (B), the polymer (B) preferablycontains 25 to 85% by weight of the polycarbonate resin (B-2) and 15 to75% by weight of the polyester resin (B-4) (provided that the totalamount of the components (B-2) and (B-4) is 100% by weight).

[0052] When the SAN resin (B-1), the polycarbonate resin (B-2) and thepolyester resin (B-4) are used in combination as the polymer (B), thepolymer (B) preferably contains 1 to 69% by weight of the copolymer(B-1), 30 to 98% by weight of the polycarbonate resin (B-2) and 1 to 69%by weight of the polyester resin (B-4) (provided that the total amountof the components (B-1), (B-2) and (B-4) is 100% by weight).

[0053] When each content of these polymers (B-1) to (B-4) is adjustedwith the above range, the resulting resin composition for a platablesubstrate is excellent in balance between moldability, mechanicalstrength, and plating properties.

[0054] When two or more kinds of these polymers are used in combinationas the other polymer (B), the content of the other polymer (B) in theresin composition (C) is from 40 to 90% by weight (based on 100% byweight of the total amount of the components (A) and (B)).

[0055] The resin composition for plating substrate of the presentinvention is obtained by mixing 100 parts by weight of the resincomposition (C) with a phosphate ester flame retardant (D) or redphosphorus flame retardant (D′) having a molecular weight of more than326.

[0056] As the phosphate ester flame retardant (D), there can be usedknown phosphate ester flame retardants having a molecular weight of morethan 326, for example, phosphate ester flame retardants manufactured byAkzo Nobel K. K., Asahi Denka Co., Ltd., Ajinomoto-Fine-Techno Co.,Inc., Albemarle Asano Corp., Great Lakes Chemical Corporation Japan, andDAIHACHI CHEMICAL INDUSTRY CO., LTD.

[0057] The phosphate ester flame retardant (D) constituting the resincomposition of the present invention includes phosphate ester compoundsrepresented by the following formula, but is not specifically limited,with the exception of a molecular weight of more than 326.

[0058] wherein R₁ to R₄ each independently represents a hydrogen atom oran organic group, excluding the case of R₁═R₂═R₃═R₄═H, A represents adi- or polyvalent organic group, 1 represents 0 or 1, m represents aninteger of 1 or more, and n represents an integer of 0 or more.

[0059] In the above formula, the organic group is an alkyl group,cycloalkyl group or aryl group which may be substituted or not. In thecase of being substituted, examples of the substituent include, but arenot limited to, alkyl group, cycloalkyl group, alkoxyl group, alkylthiogroup, aryl group, aryloxy group, and arylthio group. Also thesubstituent may be a group as a combination of these substituents (forexample, arylalkoxylalkyl group) or a group as a combination of thesesubstituents and oxygen atom, nitrogen atom, sulfur atom or the like(for example, arylsulfonylaryl group). The di- or polyvalent organicgroup means a di- or polyvalent group which is obtained by eliminatingone or more hydrogen atoms bonded to carbon atoms from the organicgroup. Examples thereof include alkylene group, (substituted)phenylenegroup, and multinucleated phenols (for example, those described frombisphenol A) and the relative position of two or more free valencies isany position. Particularly preferable examples thereof include diolcompounds of its precursor, such as hydroquinone, resorcinol,diphenylolmethane, diphenyloldimethylmethane, dihydroxybiphenyl,p,p′-dihydroxydiphenylsulfone, and dihydroxynaphthalene.

[0060] Specific examples of the phosphate ester compound includetrioctyl phosphate, tributoxyethyl phosphate, tricresyl phosphate,trixyl phosphate, cresyldiphenyl phosphate, xyldiphenyl phosphate,octyldiphenyl phosphate, diphenyl-2-ethylcresyl phosphate,tris(isopropylphenyl) phosphate, resorcinyl diphenyl phosphate,bisphenol A-bis(dicresyl phosphate) wherein R₁ to R₄ each represents analkoxy (for example, methoxy, ethoxy, or propoxy) or(substituted)phenoxy (for example, phenoxy ormethyl(substituted)phenoxy), such as bisphenol A bisphosphate,hydroquinonebisphosphate, resorcin bisphosphate, ortrioxybenzenetriphosphate, and poly phosphate such asphenylenebis(diphenyl phosphate), phenylenebis(ditolyl phosphate), orphenylenebis(dixylyl phosphate). These compounds can be used alone, ortwo or more kinds thereof can be used in combination. Among thesecompounds, trixyl phosphate, phenylenebis(diphenyl phosphate),phenylenebis(dixylyl phosphate), phenylenebis(ditolyl phosphate) andbisphenol A-bis(dicresyl phosphate) are preferable andphenylenebis(diphenyl phosphate) and phenylenebis(dixylyl phosphate) aremore preferable.

[0061] Since the phosphate ester flame retardant (D) having a molecularweight of more than 326 is hardly vaporized, it is not gasified duringmolding and a resin molded article having excellent appearance can beobtained. The molecular weight is more preferably 368 or more, and stillmore preferably 686 or more. The phosphate ester flame retardant is anenvironmentally friendly flame retardant because it is not a halogencompound.

[0062] The amount of the phosphate ester flame retardant (D) is from 5to 40 parts by weight. When the amount is less than 5 parts by weight,the resin composition for a platable substrate is insufficient in flameretardancy. On the other hand, when the amount exceeds 40 parts byweight, heat resistance and impact resistance are impaired. The amountis preferably within a range from 6 to 35 parts by weight, and morepreferably from 7 to 30 parts by weight.

[0063] In addition to the phosphate ester flame retardant (D), the resincomposition (C) may contain a known non-halogen flame retardant.Examples of the non-halogen flame retardant include inorganic flameretardant, for example, aluminum hydroxide.

[0064] The resin composition for a platable substrate of the presentinvention may comprise 100 parts by weight of the resin composition (C)and a red phosphorus flame retardant (D′) in place of the phosphateester flame retardant (D)

[0065] As the red phosphorus flame retardant (D′), for example, knownred phosphorus flame retardants manufactured by Nippon ChemicalIndustrial CO., LTD. and RINKAGAKU KOUGYO CO., LTD. can be used.Preferably, the red phosphorus flame retardant is stabilized by coatingwith a thermosetting resin, or a thermosetting resin and a metalhydroxide and examples thereof include “LP series” and “EP series”manufactured by Nippon Chemical Industrial CO., LTD., and “NOVA REDseries” and “EXCEL series” manufactured by RINKAGAKU KOUGYO CO., LTD.The red phosphorus flame retardant (D′) is hardly vaporized, it is notgasified during molding and a resin molded article having excellentappearance can be obtained. The red phosphorus flame retardant is anenvironmentally friendly flame retardant because it is not a halogencompound.

[0066] The amount of the red phosphorus flame retardant (D′) is from 2to 40 parts by weight. When the amount of the phosphorus flame retardant(D′) is less than 2 parts by weight, flame retardancy of the resincomposition for a platable substrate deteriorates. On the other hand,when the amount exceeds 40 parts by weight, impact resistance isimparted. The amount is preferably within a range from 3 to 30 parts byweight. Since the red phosphorus flame retardant (D′) alone has ignitionquality, it is preferably to be mixed previously with at least one ofthe graft copolymer (A) and/or the other polymer (B) to form amasterbatch.

[0067] In addition to the red phosphorus flame retardant (D′), the resincomposition (C) may contain a known non-halogen flame retardant.Examples of the non-halogen flame retardant include phosphate flameretardants, for example, phosphate esters such as resorcinol(diphenyl)phosphate, triallyl phosphate, and aromatic phosphate ester. Alsoinorganic flame retardants such as aluminum hydroxide can be used.

[0068] The composition of the present invention can contain auxiliaryflame retardants, for example, a compound containingpolytetrafluoroethylene or tetrafluoroethylene, or a silicone polymer inorder to prevent dripping during combustion. When using the compoundcontaining polytetrafluoroethylene or tetrafluoroethylene, the amount ispreferably 0.5 parts by weight or less based on 100 parts by weight ofthe resin composition (C).

[0069] The resin composition for a platable substrate of the presentinvention may contain an inorganic filler (E) in an amount within arange from 0.1 to 50 parts by weight, and preferably from 10 to 30 partsby weight, based on 100 parts by weight of the resin composition (C).When the amount is less than 0.1 parts by weight, sufficient effect ofimproving properties such as rigidity and thermal conductivity by theaddition of the inorganic filler (E) cannot be obtained. On the otherhand, when the amount exceeds 50 parts by weight, moldability sometimesbecome insufficient.

[0070] Examples of the inorganic filler (E) include inorganic fiberssuch as glass fibers and carbon fibers; inorganic fibers coated withmetal; inorganic materials such as wollastonite, talc, mica, glassflakes, glass beads, potassium titanate, calcium carbonate, magnesiumcarbonate, carbon black, and ketjen black; metals such as iron, copper,zinc, and aluminum, and alloys thereof; and fibers and powders made ofoxides thereof. These inorganic fillers can be used alone, or two ormore kinds thereof can be used in combination. It is particularlypreferable to use carbon fibers because high rigidity can be obtained byusing them in a small amount.

[0071] If necessary, the resin composition for a platable substrate ofthe present invention can contain various additives such as othermodifiers, releasants, photo- and thermal stabilizers, auxiliary flameretardant, antistatic agents, and dyes and pigments.

[0072] The resin composition for a platable substrate of the presentinvention can be kneaded and extruded by a conventional known kneader,and can be molded into a resin molded article by a conventional knownmolding method. Examples of the molding method include injection moldingmethod, injection compression molding method, extrusion method, blowmolding method, vacuum molding method, compressed air molding method,calendering method, and inflation molding method. Among these methods,injection molding method and injection compression molding method arepreferable because there can be obtained a resin molded article which isexcellent in mass productivity and has high dimensional stability.

[0073] An average wall thickness of the resin molded article obtained bymolding the resin composition for a platable substrate of the presentinvention varies depending on the applications and shape of the product,but is usually from 0.5 to 5.0 mm. In the case of the housing forportable devices, which requires thickness and weight reduction, theaverage wall thickness is usually from 0.5 to 1.5 mm.

[0074] Plated parts comprising a metal plating layer formed on thesurface can be obtained by optionally subjecting the resin moldedarticle to a surface roughening treatment, then to a knownelectroconductive treatment and an electroplating treatment. Theresulting plated parts are excellent in EMI shieldability, rigidity,impact resistance, and thermal conductivity.

[0075] The surface roughening treatment is conducted to prevent poorpeeling of the metal plating layer from the resin molded article and aknown method can be used. In the case in which the other polymer (B)contained in the resin composition for a platable substrate contains acopolymer (B-1), that is, it is a copolymer (B-1) alone, or a polymeralloy of a copolymer (B-1) and one or more kinds of resins selected fromthree kinds of resins such as polycarbonate resin (B-2), polyamide resin(B-3) and polyester resin (B-4), a mixed solution of chromic acid andsulfuric acid can be used. In the case in which it contains a polyamideresin (B-3), hydrochloric acid or a stannic chloride solution can beused.

[0076] The electroconductive treatment is conducted so as to enable anelectroplating treatment by imparting conductivity to the resin moldedarticle. For example, there can be used a method of forming a conductiveelectroless plating layer on the surface of a resin composition by anelectroless plating treatment.

[0077] To deposit an electroless plating layer, the surface of the resinmolded article must be coated with a metal having a catalytic action,such as palladium, by dipping the resin molded article, whose surface isroughened or not, in a tin-palladium solution or subjecting it to atreatment such as sputtering with palladium metal.

[0078] In the case in which the other polymer (B) contains the copolymer(B-1) in the method of dipping in the tin-palladium solution, since thecopolymer (B-1) contains a vinyl cyanide monomer unit, tin-palladium canbe adsorbed, thereby making it possible to perform electroless plating.Otherwise, a treatment with a surfactant, or a treatment such askneading with a resin having the other polarity or coating of thesurface must be required to adsorb tin-palladium. The treating method isnot specifically limited as long as the object of the present inventioncan be achieved.

[0079] Another method of depositing an electroless plating layerincludes a method of coating with a solution containing fine metalparticles made of nickel and depositing an electroless plating layer inthe presence of nickel particles as catalytic nuclei. Examples of theelectroless plating include copper, nickel or silver electrolessplating.

[0080] Examples of the other electroconductive treatment include amethod of kneading a resin composition for a platable substrate withcarbon black, carbon fibers, metal powders, metal fibers, carbon fibers,or plated fibers or cloth, a method of coating with a conductive coatingcomposition, and a method of sputtering or vacuum evaporation withmetal.

[0081] The following electroplating treatment can be conducted by aknown method. The metal plating layer to be formed is made of copper,nickel, cobalt, chromium, silver, or gold.

[0082] The plated parts of the present invention are obtained bysubjecting at least a portion of the resin molded article to a platingtreatment to form a metal plating layer. The resin molded article may beoptionally coated with this metal plating layer. Preferably, the entiresurface (including non-effective surface) or 90% or more of the entiresurface (including effective surface) of the resin molded article iscoated with the metal plating layer in order to sufficiently impartproperties of plated parts, for example, excellent EMI shieldability,flexural modulus, rigidity, impact resistance and thermal conductivity.

[0083] The thickness of the metal plating layer formed by the platingtreatment is preferably 5 μm or more. When the thickness is less than 5μm, the resulting plated parts are insufficient in rigidity.

[0084] In the case in which the metal plating layer is formed on frontand back surfaces of the resin molded article, a difference in thicknessbetween the metal plating layer formed on the front surface and themetal plating layer formed on the back surface is preferably 20% orless. When the difference exceeds 20%, tensile stress is produced, whenthe metal plating layer is deposited on the surface of the resin moldedarticle, differs by the position, i.e., front surface and back surface,thus causing distortion of the resin molded article and accumulation ofstress, resulting in defects.

[0085] The structure of the metal plating layer is not limited to asingle-layer structure, but may be a multi-layer structure composed oftwo or more layers. In the metal plating layer of the multi-layerstructure, the kind of metal and combination of the respective layersare not specifically limited and the thicknesses of the respectivelayers are not specifically limited if the total thickness of the metalplating layer is 5 μm or more.

[0086] The plating layer may be coated before use.

[0087] The plated parts of the present invention can be applied tohousings for PC (including laptop PC), projectors (including liquidcrystal projectors), TVs, printers, facsimile machines, copyingmachines, audio equipment such as MD players, game machines, cameras(including video cameras and digital cameras), image equipment such asvideos, musical instruments, mobile devices (electronic note books,PDAs, etc.), lighting equipment, telephones, and communication equipment(including cell phones); and fishing tackle, toys such as slingshotarticles, products for vehicles, products for furniture, sanitaryproducts, and products for building materials, and are preferablyapplied to housings for laptop PCs and portable devices.

[0088] As described above, the resin composition for a platablesubstrate is excellent in production stability such as moldability,dimensional stability, mechanical strength and plating properties, andis also environmentally friendly. High-performance plated parts havingexcellent thermal conductivity can be produced by forming a metalplating layer on a resin molded article obtained by molding the resincomposition for a platable substrate using a plating treatment.

EXAMPLES

[0089] Examples will now be described in detail. The present inventionis not limited to the following Examples. In the following Examples,parts and percentages are by weight unless otherwise specified.

[0090] Preparation of Graft Copolymer (A-1)

[0091] To 100 parts (on solid content basis) of a polybutadiene latexhaving a solid content of 35% and an average particle diameter of 0.08μm, 2 parts (on solid content basis) of a copolymer latex comprising 85%of an n-butyl acrylate unit and 15% of a methacrylic acid unit, whichhas an particle diameter of 0.08 μm, was added with stirring. Themixture was continuously stirred for 30 minutes to obtain an enlargedbutadiene rubbery polymer latex having an average particle diameter of0.28 μm.

[0092] The resulting enlarged butadiene rubbery polymer latex wascharged in a reaction vessel and 100 parts of distilled water, 4 partsof Wood Rosin emulsifier, 0.4 parts of Demor N (trade name manufacturedby Kao Corporation, formalin naphthalenesulfonate condensate), 0.04parts of sodium hydroxide and 0.7 parts of dextrose were added. When theinner temperature reached 60° C. after heating with stirring, 0.1 partsof ferrous sulfate, 0.4 parts of sodium pyrophosphate and 0.06 parts ofsodium dithionite were added. Furthermore, the following mixture wascontinuously added dropwise over 90 minutes, allowed to stand for onehour, and then cooled. Acrylonitrile  30 Parts Styrene  70 Parts Cumenhydroperoxide 0.4 Parts tert-dodecylmercaptan   1 Part

[0093] The resulting graft copolymer latex was coagulated with dilutesulfuric acid, washed, filtered, and then dried to obtain a graftcopolymer (A-1) as a dry powder.

[0094] The content of an acetone soluble matter of the graft copolymer(A-1) was 27% by weight.

[0095] Preparation of Graft Copolymer (A-2)

[0096] According to the following formulation, raw materials werecharged in a reaction vessel and the polymerization was completed whilestirring under nitrogen replacement at 50° C. for 4 hours to obtain arubber latex. n-butyl acrylate   98 Parts 1,3-butyleneglycoldimethacrylate   1 Part Allyl methacrylate   1 Part Sodiumdioctylsulfonate  2.0 Parts Deionized water  300 Parts Potassiumpersulfate  0.3 Parts Disodium phosphate dodecahydrate  0.5 Parts Sodiumhydrogenphosphate dodecahydrate  0.3 Parts

[0097] 100 Parts (solid content) of the rubber latex was charged in areaction kettle, diluted with 280 parts of deionized water and thenheated to 70° C.

[0098] Separately, 0.7 parts of benzoyl peroxide was dissolved in 100parts of a monomer mixture of acrylonitrile and styrene in a weightratio of 29:71 and, after the atmosphere was replaced by nitrogen, themonomer mixture was charged in the reaction kettle containing the rubberlatex at a rate of 30 parts/hour using a constant rate pump. After thecompletion of the addition of the entire monomer, the temperature in thesystem was raised to 80° C. and continuously stirred for 30 minutes toobtain a graft copolymer latex. The polymerization degree was 99%.

[0099] The latex thus prepared was added in an aqueous 0.15% solution(90° C.) of aluminum chloride (AlCl₃.6H₂O) in an amount of three timesas much as the entire latex while stirring, thereby to coagulate thelatex. After the completion of the addition of the entire latex, thetemperature in a coagulation tank was raised to 93° C., followed bystanding for 5 minutes. After cooling, the coagulated latex wasdehydrated using a centrifugal separator, washed and then dried toobtain a graft copolymer (A-2) as a dry powder.

[0100] The content of an acetone soluble matter of the graft copolymer(A-2) was 21% by weight.

[0101] Preparation of Graft Copolymer (A-3)

[0102] A graft copolymer containing a composite rubber ofpolybutadiene/polybutyl acrylate as a rubbery polymer was synthesized inthe following manner.

[0103] To 20 parts (on a solid content basis) of a polybutadiene latexhaving a solid content of 35% and an average particle diameter of 0.08μm, 0.4 parts (on solid content basis) of a copolymer latex comprising82% of an n-butyl acrylate unit and 18% of a methacrylic acid unit,which has an average particle diameter of 0.10 μm, was added whilestirring. The mixture was continuously stirred for 30 minutes to obtainan enlarged diene rubber latex having an average particle diameter of0.36 μm.

[0104] 20 Parts (solid content) of the resulting enlarged diene rubberlatex was transferred to a reaction kettle and 1 part of dismutatedpotassium rosinate, 150 parts of deionized water and the followingmonomer mixture were added. After the atmosphere was replaced bynitrogen, the temperature was raised to 50° C. (inner temperature). Tothe mixture, a solution prepared by dissolving 0.0002 parts of ferroussulfate, 0.0006 parts of disodium ethylenediaminetetraacetate and 0.25parts of Rongalite in 10 parts of deionized water was added. n-butylacrylate   80 Parts Allyl methacrylate 0.32 Part Ethylene glycoldimethacrylate 0.16 Parts

[0105] After the completion of the reaction, the inner temperature was75° C. The temperature was raised to 80° C. and the reaction wascontinued for one hour. As a result, the polymerization degree reached98.8% to obtain a composite rubber of an enlarged diene rubber and apolyalkyl acrylate rubber. 50 parts (solid content) of the compositerubber of the enlarged diene rubber and the polyalkyl acrylate rubberwas charged in a reaction kettle, diluted with 140 parts of deionizedwater and then heated to 70° C.

[0106] Separately, 50 parts of a graft monomer mixture of acrylonitrileand styrene in a weight of 29:71 was prepared and 0.35 parts of benzoylperoxide was dissolved, and then the atmosphere was replaced bynitrogen. The monomer mixture was charged in the reaction system at arate of 15 parts/hour using a constant rate pump. After the completionof the addition of the entire monomer, the temperature in the system wasraised to 80° C. and continuously stirred for 30 minutes to obtain agraft copolymer latex. The polymerization degree was 99%.

[0107] The latex prepared in the same manner as described above wasadded in an aqueous 0.5% solution (90° C.) of sulfuric acid in an amountof three times as much as the entire latex while stirring, thereby tocoagulate the latex. After the completion of the addition of the entirelatex, the temperature in a coagulation tank was raised to 93° C.,followed by standing for 5 minutes. After cooling, the coagulated latexwas dehydrated using a centrifugal separator, washed and then dried toobtain a graft copolymer (A-3) as a dry powder.

[0108] The content of an acetone soluble matter of the graft copolymer(A-3) was 20% by weight.

[0109] Preparation of Graft Copolymer (A-4)

[0110] A graft copolymer containing a composite rubber of polysiloxanerubber/polybutyl acrylate as a rubbery polymer was synthesized in thefollowing manner.

[0111] 96 Parts of octamethyltetracyclosiloxane, 2 parts ofγ-methacryloxypropyldimethoxymethylsilane and 2 parts of ethylorthosilicate were mixed to obtain 100 parts of a siloxane mixture. Tothe mixture, a solution prepared by dissolving 0.67 parts of sodiumdodecylbenzenesulfonate in 300 parts of distilled water was added. Themixed solution was stirred at 10000 revolutions/2 min using a homomixerand then passed through a homogenizer once under a pressure of 30 MPa toobtain a premixed organosiloxane latex. Separately, 2 parts ofdodecylbenzenesulfonic acid and 98 parts of distilled water were chargedin a reaction vessel equipped with a reagent injection container, acooling tube, a jacket heater and a stirrer to prepare an aqueous 2%dodecylbenzenesulfonic acid solution. While heating to 85° C., theaqueous solution was added dropwise in the premixed organosiloxane latexover 4 hours. After the completion of the dropwise addition, the mixturewas allowed to stand while being maintained at the same temperature forone hour, and was then cooled. The reaction solution was allowed tostand at room temperature for 48 hours and was then neutralized with anaqueous caustic soda solution. A portion of the latex (L-1) thusobtained was dried at 170° C. for 30 minutes and the solid content wasdetermined. As a result, it was 17.3%.

[0112] In a reaction vessel equipped with a reagent injection container,a cooling tube, a jacket heater and a stirrer, 119.5 parts of apolyorganosiloxane latex (L-1) and 0.8 parts of sodium polyoxyethylenealkylphenyl ether sulfate were charged and then mixed with 203 parts ofdistilled water. Furthermore, a mixture comprising 53.2 parts of n-butylacrylate, 0.21 parts of allyl methacrylate, 0.11 parts of 1,3-butyleneglycol dimethacrylate and 0.13 parts of tertiary butyl hydroperoxide wasadded. The atmosphere was replaced by nitrogen by passing a nitrogen gasthrough the reaction vessel and the temperature was raised to 60° C.After the temperature in the reaction vessel reached 60° C., an aqueoussolution prepared by dissolving 0.0001 parts of ferrous sulfate, 0.0003parts of disodium ethylenediamine tetraacetate and 0.24 parts ofRongalite in 10 parts of distilled water was added and the radicalpolymerization was initiated. The solution temperature increased to 78°C. by the polymerization of the acrylate component. This state wasmaintained for one hour, thereby to complete the polymerization of theacrylate component to obtain a composite rubber latex ofpolyorganosiloxane and a butyl acrylate rubber.

[0113] After the solution temperature in the reaction vessel decreasedto 60° C., an aqueous solution prepared by dissolving 0.4 parts ofRongalite in 10 parts of distilled water was added. Then, a mixedsolution of 11.1 parts of acrylonitrile, 33.2 parts of styrene and 0.2parts of tertiary butyl hydroperoxide was added dropwise over about onehour and the polymerization was conducted. After the completion of thedropwise addition and standing for one hour, an aqueous solutionprepared by dissolving 0.0002 parts of ferrous sulfate, 0.0006 parts ofdisodium ethylenediamine tetraacetate and 0.25 parts of Rongalite in 10parts of distilled water was added. Then, a mixed solution of 7.4 partsof acrylonitrile, 22.2 parts of styrene and 0.1 parts of tertiary butylhydroperoxide was added dropwise over about 40 minutes. After thecompletion of the dropwise addition and standing for one hour, themixture was cooled to obtain a latex of a graft copolymer prepared bygrafting the composite rubber of polyorganosiloxane and the butylacrylate rubber with an acrylonitrile-styrene copolymer.

[0114] Then, 150 parts of an aqueous solution prepared by dissolving 5%of calcium acetate was heated to 60° C. and stirred. In the aqueoussolution, 100 parts of the latex of the graft copolymer was graduallyadded dropwise, thereby to coagulate the latex. The deposit wasseparated, washed and then dried to obtain a graft copolymer (A-4) as adry powder.

[0115] The content of an acetone soluble matter of the graft copolymer(A-4) was 26% by weight.

[0116] Preparation of Copolymer (B-1a)

[0117] A copolymer containing 30% of an acrylonitrile unit and 70% of astyrene unit was prepared by a suspension polymerization method.

[0118] Polycarbonate Resin (B-2a)

[0119] As the polycarbonate resin (B-2a), “7022A” manufactured byMitsubishi Engineering-Plastics Corporation was used.

[0120] Polyamide Resin (B-3a)

[0121] As the polyamide resin (B-3a), “1011FB” manufactured by UBEINDUSTRIES, LTD. was used.

[0122] Polybutyl Terephthalate Resin (B-4a)

[0123] As the polybutyl terephthalate resin (B-4a), “TAFPET PBT N1000”manufactured by Mitsubishi Rayon Co., Ltd. was used.

Examples 1 to 38 and Comparative Examples 1 to 11

[0124] According to the formulations shown in Tables 1 to 3, a graftcopolymer (A), the other polymer (B), a red phosphorus flame retardant(D) and an inorganic filler (E) were respectively mixed to prepare resincompositions for a platable substrate. Each respective graft copolymer(A) contains an acetone soluble matter and the acetone soluble matter iscounted as the other polymer (B). Therefore, in the tables, the actualamount and the net amount excluding the amount of the acetone solublematter are described in the column of the graft copolymer (A), and alsoan amount of the acetone soluble matter, counted as the other polymer(B), in the graft copolymer (A) was described. As the phosphate esterflame retardant (D), “ADEKASTAB FP-500” (molecular weight: 686,described as D-1 in the table) and “ADEKASTAB FP-700” (molecular weight:692, described as D-2 in the table) manufactured by Asahi Denka Co.,Ltd.; “CR-733S” (molecular weight: 574, described as D-3 in the table)and “PX-200” (molecular weight: 686, described as D-4 in the table)manufactured by DAIHACHI CHEMICAL INDUSTRY CO., LTD.; and “Kronitex TCP”(molecular weight: 368, described as D-5 in the table), “Kronitex TXP”(molecular weight: 410, described as D-6 in the table) and “REOFOS BAPP”(molecular weight: 692, described as D-7 in the table) manufactured byAjinomoto-Fine-Techno Co., Inc., were used. In Comparative Examples 1 to3, as the flame retardant, triphenylene phosphate having a molecularweight of 326 (described as F-1 in the table) was used. Regarding theinorganic filler (E), “ECS03-T191” (described as GF in the table)manufactured by Nippon Electric Glass Co., Ltd., was used as the glassfiber and “TR06U” (described as CF in the table) manufactured byMitsubishi Rayon Co., Ltd., was used as the carbon fibers.

[0125] Flame retardancy, moldability and plating properties of theresulting respective resin compositions for plating substrate wereevaluated by the procedures described hereinabove. After the respectiveresin compositions for plating substrate were molded, a metal platinglayer was formed according to the following plating process and variousphysical properties were evaluated.

[0126] These results are shown in Tables 4 to 9.

[0127] Flame Retardancy

[0128] Test pieces (12.7 mm×127 mm×1.0 mm [thickness]) were made and acombustion test was carried out in accordance with UL94.

[0129] In the tables, abbreviations are as follows.

[0130] ⊚: V-0 grade

[0131] ◯: V-2 grade

[0132] ×: V-2 grade or lower

[0133] The combustion test was performed by the following procedure inaccordance with UL94.

[0134] The lower end of the vertically held test piece was caused tocontact the flame of a burner for 10 seconds, and the combustion of thetest piece was stopped immediately after the flame ceased to be appliedto the test piece. The flame of a burner is applied again to the testpieces and the same operation was conducted. The flame retardancy isevaluated by the total of a flame maintenance time after the completionof the first flame contact, a flame maintenance time after thecompletion of the second flame contact and a non-flame maintenance timeas well as the presence or absence of dripping. Furthermore, with regardto UL-94, the respective V grade criteria may be summarized as shownbelow.

[0135] V-0: The first flame maintenance time was less than 10 secondsand the total of the second flame maintenance time and non-flamemaintenance time was less than 30 seconds. Furthermore, none of the testpieces exhibited any dripping.

[0136] V-1: The first flame maintenance time was more than 10 secondsand 30 seconds or less and the total of the second flame maintenancetime and non-flame maintenance time was more than 30 seconds and 60seconds or less. Furthermore, none of the test pieces exhibited anydripping.

[0137] V-2: The first flame maintenance time was more than 10 secondsand 30 seconds or less and the total of the second flame maintenancetime and non-flame maintenance time was more than 30 seconds and 60seconds or less. Furthermore, the test pieces exhibited dripping.

[0138] Moldability

[0139] (1) Occurrence of Burrs

[0140] Box-shaped molded articles (297 mm×185 mm×20 mm [1.25 mm inthickness]) were formed and the presence or absence of burrs wasobserved.

[0141] In the tables, abbreviations are as follows.

[0142] ◯: none

[0143] ×: burrs

[0144] (2) Occurrence of Warp

[0145] Box-shaped molded articles (297 mm×185 mm×20 mm [1.25 mm inthickness]) were formed and the presence or absence of warp of 2 mm ormore was observed.

[0146] In the tables, abbreviations are as follows.

[0147] ◯: none

[0148] ×: warp

[0149] (3) Gas Deposition

[0150] Box-shaped molded articles (297 mm×185 mm×20 mm [1.25 mm inthickness]) were continuously formed (100 shots) and the presence orabsence of gas deposition on the mold surface was confirmed.

[0151] In the tables, abbreviations are as follows.

[0152] ⊚: no gas deposit

[0153] ◯: gas blooming (slight gas deposit) after 100 shots

[0154] Δ: gas blooming (slight gas deposit) after 80 shots

[0155] ×: gas deposit after 50 shots

[0156] Plating Properties

[0157] By the following plating process, box-shaped molded articles (297mm×185 mm×20 mm [1.25 mm in thickness]) were subjected to a platingtreatment and the presence or absence of poor plating was observed.

[0158] In the tables, abbreviations are as follows.

[0159] ⊚: no poor plating

[0160] ◯: slightly poor plating (0 to 1%)

[0161] Δ: slightly poor plating (1 to 5%)

[0162] ×: poor plating (5% or more)

[0163] Flexural Modulus

[0164] The flexural modulus as an index of rigidity modulus wasmeasured. By the following plating process, test pieces (10 mm×100 mm×4mm [in thickness]) were subjected to a plating treatment and theflexural modulus was measured in accordance with ASTM D-790.

[0165] Izod Impact Strength

[0166] By the following plating process, test pieces (12.7 mm×63.5mm×3.2 mm [in thickness]) were subjected to a plating treatment and theflexural modulus was measured in accordance with ASTM D-256. It wasrated that test pieces with a value of 200 J/m as measured by this testmethod were suitable for practical use.

[0167] Thermal Cycle Properties

[0168] By the following plating process, plates (100 mm×100 mm×3 mm [inthickness]) were subjected to a plating treatment. Then, these plateswere test under the following thermal cycle conditions and the presenceor absence of blistering of the plating layer was confirmed.

[0169] Thermal Cycle Conditions

[0170] Three cycles, each cycle comprising heating at −30° C. for onehour, heating at 23° C. for 15 min, heating at 80° C. for one hour andheating at 23° C. for one hour, were carried out.

[0171] In the tables, abbreviations are as follows.

[0172] ◯: no change

[0173] ×: blistering occurred in the vicinity of gates

[0174] ××: blistering also occurred at other portions

[0175] ×××: blistering occurred over plating layer

[0176] Thermal Conductivity

[0177] By the following plating process, plates (100 mm×100 mm×3 mm [inthickness]) were subjected to a plating treatment and the thermalconductivity was measured by using a Shotherm QTM (quick thermalconductivity meter manufactured by Showa Denko K. K.).

[0178] Plating Process

[0179] (1) degreasing (at 60° C. for 3 min)→(2) washing→(3) etching (400g/l of CrO₃, 200 cc/l of H₂SO₄, at 60° C. for 8 min)→(4) washing→(5)acid treatment (at normal temperature for 1 min)→(6) washing→(7)catalyzing treatment (at 25° C. for 3 min)→(8) washing→(9) activationtreatment (at 40° C. for 5 min)→(10) washing→(11) chemical nickelplating→(12) washing→(13) copper electroplating (plating layer having athickness of 15 μm, at 20° C. for 20 min)→(14) washing→(15) nickelelectroplating (plating layer having a thickness of 10 μm, at 55° C. for15 min)→(16) washing →(17) drying

[0180] In Examples 19 and 20, an electroplating treatment was carriedout in the same manner, except that the processes (13) and (14) wereeliminated and the time of the process (15) was changed to 6 min, aplating layer having a thickness of 4 μm was formed.

[0181] As is apparent from Tables 4 to 6, all resin compositions for aplatable substrate of the Examples were excellent in flame retardancy,moldability and plating properties, and plated plates produced byforming a metal plating layer on a resin molded article obtained bymolding the resin composition for a platable substrate was excellent inflexural modulus, impact strength and thermal conductivity and alsoexcellent in thermal cycle properties (plating properties). TABLE 1Graft polymer (A) Net amount excluding Rubbery polymer Actual amountamount of acetone Content Average particle Examples A-1 A-2 A-3 A-4soluble matter (% by weight) diameter (μm)  1 40 29.2 20 0.28  2 40 31.620 0.25  3 40 32 20 0.36  4 40 29.6 20 0.14  5 40 32 20 0.36  6 40 32 200.36  7 20 14.6 10 0.28  8 20 15.8 10 0.25  9 20 16 10 0.36 10 20 14.810 0.14 11 20 16 10 0.36 12 20 16 10 0.36 13 20 16 10 0.36 14 20 16 100.36 15 25 20 12.5 0.36 16 25 20 12.5 0.36 17 15 12 7.5 0.36 18 15 11.17.5 0.14 19 40 32 20 0.36 20 20 16 10 0.36 Other polymer (B) Acetonesoluble Flame retardant (D) Inorganic filler (E) Examples matter in (A)B-1a B-2a B-3a B-4a D-1 GF CF  1 10.8 60 30  2 8.4 60 30  3 8 60 30  410.4 60 30  5 8 60 30 25  6 8 60 30 10  7 5.4 10 70 20  8 4.2 10 70 20 9 4 10 70 20 10 5.2 10 70 20 11 4 10 70 20 25 12 4 10 70 20 10 13 4 1070 20 20 14 4 10 70 20 30 15 5 25 50 30 10 16 5 25 50 30 10 17 3 70 1520 10 18 3.9 10 70  5 20 10 19 8 60 30 10 20 4 10 70 20 10

[0182] TABLE 2 Graft polymerization (A) Rubbery polymer Actual amountNet amount excluding amount Content Average particle Examples A-3 ofacetone soluble matter (% by weight) diameter (μm) 21 20 16 10 0.36 2220 16 10 0.36 23 20 16 10 0.36 24 20 16 10 0.36 25 20 16 10 0.36 26 2016 10 0.36 27 20 16 10 0.36 28 20 16 10 0.36 29 20 16 10 0.36 30 20 1610 0.36 31 20 16 10 0.36 32 20 16 10 0.36 33 20 16 10 0.36 34 20 16 100.36 35 20 16 10 0.36 36 20 16 10 0.36 37 20 16 10 0.36 38 20 16 10 0.36Other polymer (B) Inorganic Acetone soluble Flame retardant (D) filler(E) Examples matter in (A) B-1a B-2a D-2 D-3 D-4 D-5 D-6 D-7 GF CF 21 410 70 20 22 4 10 70 20 25 23 4 10 70 20 10 24 4 10 70 20 25 4 10 70 2025 26 4 10 70 20 10 27 4 10 70 20 28 4 10 70 20 25 29 4 10 70 20 10 30 410 70 20 31 4 10 70 20 25 32 4 10 70 20 10 33 4 10 70 20 34 4 10 70 2025 35 4 10 70 20 10 36 4 10 70 20 37 4 10 70 20 25 38 4 10 70 20 10

[0183] TABLE 3 Com- Rubbery polymer par- Graft polymer (A) Average ativeNet amount excluding particle Exam- Actual amount amount of acetoneContent diameter ples A-2 A-3 soluble matter (% by weight) (μm)  1 2015.8 10 0.25  2 20 15.8 10 0.25  3 20 15.8 10 0.25  4 8 6.4 4 0.36  5 8064 40 0.36  6 8 6.4 4 0.36  7 80 64 40 0.36  8 40 32 20 0.36  9 25 2012.5 0.36 10 40 32 20 0.36 11 25 20 12.5 0.36 Other polymer (B) FlameInorganic Comparative Acetone soluble retardant filler (E) Examplesmatter in (A) B-1a B-2a D-1 F-1 GF CF  1 4.2 5 75 15  2 4.2 5 75 15 25 3 4.2 5 75 15 10  4 1.6 92 30  5 16 35 30  6 1.6 22 70 20  7 16 35 20 8 8 60 4  9 5 10 70 4 10 8 60 50 11 5 10 70 50

[0184] TABLE 4 Various properties Moldability Flexural Izod impactThermal Thermal Flame Occurrence Occurrence Gas Plating modulus strengthcycle conductivity Examples retardancy of burrs of warp depositionproperties (MPa) (J/m) properties (W/m · ° C.) 1 ◯ ◯ ◯ ⊚ ⊚ 6800 not ◯0.60 fractured 2 ◯ ◯ ◯ ⊚ ⊚ 6800 not ◯ 0.60 fractured 3 ◯ ◯ ◯ ⊚ ⊚ 6800not ◯ 0.60 fractured 4 ◯ ◯ ◯ ⊚ ⊚ 6800 not ◯ 0.60 fractured 5 ◯ ◯ ◯ ⊚ ⊚13500 410 ◯ 0.80 6 ◯ ◯ ◯ ⊚ ⊚ 14000 400 ◯ 0.84 7 ⊚ ◯ ◯ ⊚ ⊚ 7000 not ◯0.60 fractured 8 ⊚ ◯ ◯ ⊚ ⊚ 7000 not ◯ 0.60 fractured 9 ⊚ ◯ ◯ ⊚ ⊚ 7000not ◯ 0.60 fractured 10 ⊚ ◯ ◯ ⊚ ⊚ 7000 not ◯ 0.61 fractured 11 ⊚ ◯ ◯ ⊚ ⊚14000 550 ◯ 0.81 12 ⊚ ◯ ◯ ⊚ ⊚ 15000 440 ◯ 0.85 13 ⊚ ◯ ◯ ⊚ ⊚ 21000 490 ◯0.90 14 ⊚ ◯ ◯ ⊚ ⊚ 25000 460 ◯ 0.92 15 ◯ ◯ ◯ ⊚ ⊚ 15000 580 ◯ 0.84 16 ◯ ◯◯ ⊚ ⊚ 14000 430 ◯ 0.85 17 ⊚ ◯ ◯ ⊚ ⊚ 14000 560 ◯ 0.82 18 ⊚ ◯ ◯ ⊚ ⊚ 15000440 ◯ 0.85 19 ◯ ◯ ◯ ⊚ ⊚ 7200 240 ◯ 0.70 20 ⊚ ◯ ◯ ⊚ ⊚ 8000 240 ◯ 0.72

[0185] TABLE 5 Various properties Moldability Flexural Izod impactThermal Thermal Flame Occurrence Occurrence Gas Plating modulus strengthcycle conductivity Examples retardancy of burrs of warp depositionproperties (MPa) (J/m) properties (W/m · ° C.) 21 ⊚ ◯ ◯ ⊚ ⊚ 7000 not ◯0.60 fractured 22 ⊚ ◯ ◯ ⊚ ⊚ 14000 550 ◯ 0.81 23 ⊚ ◯ ◯ ⊚ ⊚ 15000 440 ◯0.85 24 ⊚ ◯ ◯ ◯ ⊚ 7000 not ◯ 0.60 fractured 25 ⊚ ◯ ◯ ◯ ⊚ 14000 540 ◯0.81 26 ⊚ ◯ ◯ ◯ ⊚ 15000 430 ◯ 0.85 27 ⊚ ◯ ◯ ⊚ ⊚ 7000 not ◯ 0.60fractured 28 ⊚ ◯ ◯ ⊚ ⊚ 14000 550 ◯ 0.81 29 ⊚ ◯ ◯ ⊚ ⊚ 15000 440 ◯ 0.85 30⊚ ◯ ◯ Δ Δ 7000 not ◯ 0.60 fractured 31 ⊚ ◯ ◯ Δ Δ 14000 550 ◯ 0.81 32 ⊚ ◯◯ Δ Δ 15000 440 ◯ 0.85 33 ⊚ ◯ ◯ ◯ ◯ 7000 not ◯ 0.60 fractured 34 ⊚ ◯ ◯ ◯◯ 14000 550 ◯ 0.81 35 ⊚ ◯ ◯ ◯ ◯ 15000 440 ◯ 0.85 36 ⊚ ◯ ◯ ⊚ ⊚ 7000 not ◯0.60 fractured 37 ⊚ ◯ ◯ ⊚ ⊚ 14000 540 ◯ 0.81 38 ⊚ ◯ ◯ ⊚ ⊚ 15000 430 ◯0.85

[0186] TABLE 6 Various properties Compar- Moldability Flexural Izodimpact Thermal Thermal ative Flame Occurrence Occurrence Gas Platingmodulus strength cycle conductivity Examples retardancy of burrs of warpdeposition properties (MPa) (J/m) properties (W/m · ° C.) 1 ⊚ ◯ ◯ X X7000 not ◯ 0.60 fractured 2 ⊚ ◯ ◯ X X 13300 430 ◯ 0.81 3 ⊚ ◯ ◯ X X 13500320 ◯ 0.86 4 ◯ ◯ ◯ ⊚ ⊚ 7000 330 XX 0.60 5 X ◯ ◯ ⊚ ⊚ 6500 not XX 0.60fractured 6 ⊚ ◯ ◯ ⊚ ⊚ 7200 360 XX 0.60 7 X ◯ ◯ ⊚ ⊚ 6700 not XX 0.60fractured 8 X ◯ ◯ ⊚ ⊚ 7000 not ◯ 0.60 fractured 9 X ◯ ◯ ⊚ ⊚ 7200 not ◯0.60 fractured 10 ◯ ◯ ◯ ⊚ ⊚ 6300 100 ◯ 0.60 11 ⊚ ◯ ◯ ⊚ ⊚ 6500 120 ◯ 0.60

Examples 39 to 58 and Comparative Examples 12 to 20

[0187] According to the formulations shown in Tables 7 and 8, a graftcopolymer (A), the other polymer (B), a red phosphorus flame retardant(D′) and an inorganic filler (E) were respectively mixed to prepareresin compositions for a platable substrate. Each respective graftcopolymer (A) contains an acetone soluble matter and the acetone solublematter is counted as the other polymer (B). Therefore, in the tables, anactual amount and a net amount excluding the amount of the acetonesoluble matter are described in the column of the graft copolymer (A),and also an amount of the acetone soluble matter, counted as the otherpolymer (B), in the graft copolymer (A) was described. As the redphosphorus flame retardant (D′), “Nova Excel 140” manufactured byRINKAGAKU KOUGYO CO., LTD. was used. As the inorganic filler (E), thesame fibers as those in Examples 1 to 38 were used.

[0188] In the same manner as in Examples 1 to 38, flame retardancy,moldability and plating properties of the resulting respective resincompositions for plating substrate were evaluated by the proceduresdescribed hereinabove.

[0189] These results are shown in Tables 9 and 10.

[0190] As is apparent from the results shown in Tables 9 and 10, allresin compositions for a platable substrate of these examples wereexcellent in flame retardancy, moldability and plating properties, andalso plated parts comprising a resin molded article obtained by moldingand a metal plating layer provided on the resin molded article wasexcellent in flexural modulus, impact strength, thermal conductivity andthermal cycle properties (plating properties). TABLE 7 Graft polymer (A)Net amount excluding Rubbery polymer Actual amount amount of acetoneContent Average particle Examples A-1 A-2 A-3 A-4 soluble matter (% byweight) diameter (μm) 39 40 29.2 20 0.28 40 40 31.6 20 0.25 41 40 32.020 0.36 42 40 29.6 20 0.14 43 40 32.0 20 0.36 44 40 32.0 20 0.36 45 2518.3 12.5 0.28 46 25 19.8 12.5 0.25 47 25 20.0 12.5 0.36 48 25 18.5 12.50.14 49 25 20.0 12.5 0.36 50 25 20.0 12.5 0.36 51 25 20.0 12.5 0.36 5225 20.0 12.5 0.36 53 25 20.0 12.5 0.36 54 25 20.0 12.5 0.36 55 25 20.012.5 0.36 56 20 14.8 10 0.14 57 40 32.0 20 0.36 58 25 20.0 12.5 0.36Other polymer (B) Acetone soluble Flame retardant Inorganic filler (E)Examples matter in (A) B-1a B-2a B-3a B-4a (D′) GF CF 39 10.8 60 30 408.4 60 30 41 8.0 60 30 42 10.4 60 30 43 8.0 60 30 25 44 8.0 60 30 10 456.7 25 50 3 46 5.2 25 50 3 47 5.0 25 50 3 48 6.5 25 50 3 49 5.0 25 50 325 50 5.0 25 50 3 10 51 5.0 25 50 3 20 52 5.0 25 50 3 30 53 5.0 25 50 3010 54 5.0 25 50 30 10 55 5.0 50 25 3 10 56 5.2 20 50 10 3 10 57 8.0 6030 10 58 5.0 25 50 3 10

[0191] TABLE 8 Compar- Graft polymer (A) Rubbery polymer ative Actualamount Net amount excluding amount Content Average particle Examples A-3of acetone soluble matter (% by weight) diameter (μm) 12 0 13 8 6.4 40.36 14 65 64.0 32.5 0.36 15 8 6.4 4 0.36 16 65 64.0 32.5 0.36 17 4032.0 20 0.36 18 25 20.0 12.5 0.36 19 40 32.0 20 0.36 20 25 20.0 12.50.36 Other polymer (B) Comparative Acetone soluble Flame retardantInorganic filler (E) Examples matter in (A) B-1a B-2a B-3a (D′) CF 12100 30 20 13 1.6 92 30 14 16.0 35 30 15 1.6 42 50 3 16 16.0 35 3 17 8.060 1 18 5.0 25 50 1 19 8.0 60 50 20 5.0 25 50 50

[0192] TABLE 9 Various properties Moldability Flexural Izod impactThermal Thermal Flame Occurrence Occurrence Gas Plating modulus strengthcycle conductivity Examples retardancy of burrs of warp depositionproperties (MPa) (J/m) properties (W/m · ° C.) 39 ⊚ ◯ ◯ ⊚ ⊚ 7000 not ◯0.60 fractured 40 ⊚ ◯ ◯ ⊚ ⊚ 7000 not ◯ 0.60 fractured 41 ⊚ ◯ ◯ ⊚ ⊚ 7000not ◯ 0.60 fractured 42 ⊚ ◯ ◯ ⊚ ⊚ 7000 not ◯ 0.60 fractured 43 ⊚ ◯ ◯ ⊚ ⊚13500 410 ◯ 0.80 44 ⊚ ◯ ◯ ⊚ ⊚ 14000 400 ◯ 0.84 45 ⊚ ◯ ◯ ⊚ ⊚ 7000 not ◯0.60 fractured 46 ⊚ ◯ ◯ ⊚ ⊚ 7000 not ◯ 0.60 fractured 47 ⊚ ◯ ◯ ⊚ ⊚ 7000not ◯ 0.60 fractured 48 ⊚ ◯ ◯ ⊚ ⊚ 7000 not ◯ 0.61 fractured 49 ⊚ ◯ ◯ ⊚ ⊚14000 550 ◯ 0.81 50 ⊚ ◯ ◯ ⊚ ⊚ 15000 440 ◯ 0.85 51 ⊚ ◯ ◯ ⊚ ⊚ 21000 490 ◯0.90 52 ⊚ ◯ ◯ ⊚ ⊚ 25000 460 ◯ 0.92 53 ⊚ ◯ ◯ ⊚ ⊚ 15000 580 ◯ 0.84 54 ⊚ ◯◯ ⊚ ⊚ 14000 430 ◯ 0.85 55 ⊚ ◯ ◯ ⊚ ⊚ 14000 560 ◯ 0.82 56 ⊚ ◯ ◯ ⊚ ⊚ 15000440 ◯ 0.85 57 ⊚ ◯ ◯ ⊚ ⊚ 7200 240 ◯ 0.70 58 ⊚ ◯ ◯ ⊚ ⊚ 8000 240 ◯ 0.72

[0193] TABLE 10 Various properties Compar- Moldability Flexural Izodimpact Thermal Thermal ative Flame Occurrence Occurrence Gas Platingmodulus strength cycle conductivity Examples retardancy of burrs of warpdeposition properties (MPa) (J/m) properties (W/m · ° C.) 12 ⊚ X X ⊚ ⊚23000 650 XX 0.80 13 ⊚ ◯ ◯ ⊚ ⊚ 7000 330 XX 0.60 14 X ◯ ◯ ⊚ ⊚ 7000 not XX0.60 fractured 15 ⊚ ◯ ◯ ⊚ ⊚ 7000 360 XX 0.60 16 X ◯ ◯ ⊚ ⊚ 7000 not XX0.60 fractured 17 X ◯ ◯ ⊚ ⊚ 7000 not ◯ 0.60 fractured 18 X ◯ ◯ ⊚ ⊚ 7000not ◯ 0.60 fractured 19 ⊚ ◯ ◯ ⊚ ⊚ 7000 120 ◯ 0.60 20 ⊚ ◯ ◯ ⊚ ⊚ 7000 150◯ 0.60

INDUSTRIAL APPLICABILITY

[0194] As described above, the resin composition for a platablesubstrate of the present invention is excellent in production stabilitysuch as moldability, dimensional stability, mechanical strength andplating properties, and is also environmentally friendly. Therefore,excellent plated parts having good thermal conductivity can be providedby forming a metal plating layer on a resin molded article obtained bymolding the resin composition for a platable substrate using a platingtreatment. Thus, the present invention is of great industrialsignificance.

[0195] The invention may be embodied in other specific forms withoutdeparting from the spirit or essential properties thereof. The presentembodiment is therefore to be considered in all respects as illustrativeand not restrictive, the scope of the invention being indicated by theappended claims rather than by the foregoing description and all changeswhich come within the meaning and range of equivalency of the claims aretherefore intended to be embraced therein.

1. A resin composition for a platable substrate, comprising: 100 partsby weight of a resin composition (C) comprising 10 to 60% by weight of agraft copolymer (A) prepared by graft polymerization of a rubberypolymer (A1) and a monomer component (A2) containing an aromatic alkenylcompound monomer unit (a) and a vinyl cyanide compound monomer unit (b)and 40 to 90% by weight of the other polymer (B) (provided that thetotal amount of the components (A) and (B) is 100% by weight), and 5 to40 parts by weight of a phosphate ester flame retardant (D) having amolecular weight of more than 326 or 2 to 40 parts by weight of a redphosphorus flame retardant (D′).
 2. The resin composition for a platablesubstrate according to claim 1, wherein the other polymer (B) is atleast one kind selected from the group consisting of a copolymer (B-1)composed of a monomer component containing an aromatic alkenyl compoundmonomer unit (a) and a vinyl cyanide compound monomer unit (b), apolycarbonate resin (B-2), a polyamide resin (B-3) and a polyester resin(B-4).
 3. The resin composition for a platable substrate according toclaim 1, wherein the content of the rubbery polymer (A1) in the resincomposition (C) is from 5 to 25% by weight and an average particlediameter of the rubbery polymer (A1) is from 0.1 to 0.6 μm.
 4. The resincomposition for a platable substrate according to claim 1, which furthercomprises an inorganic filler (E) in an amount of 0.1 to 50 parts byweight based on 100 parts by weight of the resin composition (C).
 5. Theresin composition for a platable substrate according to claim 4, whereinthe inorganic filler (E) is carbon fiber.
 6. A resin molded articleproduced by molding the resin composition for plating substrateaccording to claim
 1. 7. Plated parts comprising the resin moldedarticle according to claim 6 and a metal plating layer on at least aportion of the surface of the resin molded article.
 8. Plated partsaccording to claim 7, wherein the metal plating layer is formed by anelectroplating treatment.
 9. Plated parts according to claim 7, whereinthe metal plating layer has a thickness of 5 μm or more.